Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
hanh sinh » hanh tinh, hanh dinh, hinh sinh
cua nhung » va nhung
dang hanh » dang thanh, ban hanh, dang hung
sinh cua » manh cua, dinh cuu, sinh va
dang van » hoang van, hang va

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu quang)) - hanh sinh cua nhung ((dang hanh) OR (dang van)) trung tam~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) or (hieu quang)) - hanh sinh cua nhung ((dang hanh) OR (dang van)) trung tam~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (hieu quang)) - hanh sinh cua nhung ((dang hanh) OR (dang van)) trung tam*.